Ink jet printer with self-regulating refilling system

Abstract

An ink jet printer (30) includes a print head reservoir container (14) having a colorant refill needle (26) extending from the exterior to the interior thereof and a vacuum port (24) therein, and a service station (50) having a valve (52) that controllably connects the refill needle (26) to a colorant supply (56) and controllably connects the vacuum port (24) to a vacuum manifold (60). Colorant is added to the reservoir container (14) by first drawing a vacuum on the interior of the reservoir container (14) with the vacuum manifold (60) connected to the vacuum port (24) and with the refill needle (26) sealed, and then sealing the vacuum port (24), placing the refill needle (26) in communication with the exterior colorant supply (56), and permitting the partial vacuum in the interior of the reservoir container (14) to draw colorant from the colorant supply (56) into the interior of the reservoir container (14).

What is claimed is: 
     
       1. An ink jet printer, comprising: print head means for ejecting droplets of a colorant, including a reservoir container that holds a volume of the colorant,   a colorant ejector in communication with the reservoir container that receives a flow of colorant from the reservoir container and ejects droplets of colorant therefrom under command,   a vacuum port in the wall of the reservoir container, and   refill tube means for refilling the reservoir, the refill tube means communicating from the exterior of the reservoir container into the interior of the reservoir container; and     a service station for adding colorant to the reservoir container, including a colorant supply,   a vacuum manifold,   valve means for controllably placing the vacuum manifold in communication with the vacuum port and sealing the colorant supply from the refill tube means in a first refilling position, and for controllably sealing the vacuum manifold from communication with the vacuum port and placing the colorant supply in communication with the refill tube means in a second refilling position, and   support means for holding the reservoir container in contact with the valve means, for preventing ejection of colorant, and for preventing introduction of air into the print head.     
     
     
       2. The ink jet printer of claim 1, wherein the reservoir container is at least partially refilled with a colorant-retaining foam mass. 
     
     
       3. The ink jet printer of claim 1, wherein the vacuum manifold includes a vacuum pump. 
     
     
       4. The ink jet printer of claim 3, wherein the vacuum pump is a piston pump. 
     
     
       5. The ink jet printer of claim 1, wherein the valve means includes a three-position valve having a first position wherein both the vacuum manifold and the colorant supply are sealed from communication with the interior of the reservoir container,   a second position wherein the vacuum manifold is placed in communication with the vacuum port and the colorant supply is sealed from communication with the refill tube means, and   a third position wherein the vacuum manifold is sealed from communication with the vacuum port and the colorant supply is placed in communication with the refill tube means.   
     
     
       6. The ink jet printer of claim 1, wherein the valve means includes a two-position valve having a first position wherein the vacuum manifold is placed in communication with the vacuum port and the colorant supply is sealed from communication with the refill tube means, and   a second position wherein the vacuum manifold is sealed from communication with the vacuum port and the colorant supply is placed in communication with the refill tube means.   
     
     
       7. The ink jet printer of claim 1, wherein the valve means includes a rotary valve. 
     
     
       8. The ink jet printer of claim 1, wherein the valve means includes a slide valve. 
     
     
       9. An ink jet printer operable with print head means for ejecting droplets of a colorant, the print head means including a reservoir container that holds a volume of the colorant, an ink ejector that receives colorant from the reservoir container and ejects droplets of colorant therefrom, and a refill tube extending from the exterior of the reservoir container into the interior of the reservoir container, the printer comprising: a service station whereat colorant is added to the reservoir container, including a colorant supply,   a vacuum manifold,   valve means for controllably placing the vacuum manifold in communication with the interior of the reservoir container and sealing the colorant supply from the refill tube in a first refilling position, and for controllably sealing the vacuum manifold from communication with the reservoir container and placing the colorant supply in communication with the refill tube in a second refilling position, and   support means for holding the reservoir container in contact with the valve means, for preventing ejection of colorant, and for preventing introduction of air into the print head.     
     
     
       10. The ink jet printer of claim 9, wherein the valve means includes a three-position valve having a first position wherein both the vacuum manifold and the colorant supply are sealed from communication with the interior of the reservoir container,   a second position wherein the vacuum manifold is placed in communication with the vacuum port and the colorant supply is sealed from communication with the refill tube means, and   a third position wherein the vacuum manifold is sealed from communication with the vacuum port and the colorant supply is placed in communication with the refill tube means.   
     
     
       11. The ink jet printer of claim 9, wherein the valve means includes a two-position valve having a first position wherein the vacuum manifold is placed in communication with the vacuum port and the colorant supply is sealed from communication with the refill tube means, and   a second position wherein the vacuum manifold is sealed from communication with the vacuum port and the colorant supply is placed in communication with the refill tube means.   
     
     
       12. The ink jet printer of claim 9, wherein the valve means includes a rotary valve. 
     
     
       13. The ink jet printer of claim 9, wherein the valve means includes a slide valve. 
     
     
       14. The ink jet printer of claim 9, wherein the vacuum manifold includes a vacuum pump. 
     
     
       15. The ink jet printer of claim 14, wherein the vacuum pump is a piston pump. 
     
     
       16. An ink jet print head, comprising: a reservoir container having a foam mass and adapted for holding a supply of the colorant, the reservoir container having no instrumentation therein for measuring liquid level within the container;   an ink ejector that receives colorant from the reservoir container and ejects colorant therefrom;   a vacuum port in the wall of the reservoir container; and   a refill tube inserted from the exterior of the reservoir container into the foam mass within the reservoir container, whereby the vacuum port and the refill tube cooperate to permit refilling of the reservoir container without overfilling, and without requiring any level-measuring instrumentation within the container.   
     
     
       17. A process for adding colorant to the print head of an ink jet printer, comprising the steps of: furnishing a colorant reservoir container;   creating a partial vacuum in the interior of the reservoir container using a vacuum manifold;   sealing the interior of the reservoir container from the vacuum manifold: and, after the step of sealing,   placing the interior of the reservoir container into fluid communication with a supply of the colorant and permitting colorant to be drawn into the interior of the reservoir container by the partial vacuum created in the step of creating.   
     
     
       18. An ink jet print head, comprising: a reservoir container having a foam mass and adapted for holding a supply of a colorant, the reservoir container having no instrumentation therein for measuring liquid level within the container;   an ink ejector that receives colorant from the reservoir container and ejects colorant therefrom; and   a refill port in the wall of the reservoir container, the refill port being adapted to permit the reservoir to be refilled with colorant without requiring instrumentation to monitor the toner level within the container.   
     
     
       19. The print head of claim 18, further including a refill tube extending from the refill port into the foam mass within the interior of the reservoir container.   
     
     
       20. The print head of claim 19, further including a vacuum port in the wall of the reservoir container.